void timetest() {
  TDatime sdate(2006, 5, 20, 0, 0, 0);
  TH1F *h = new TH1F("h", "", 86400, 0, 86400);
  h->GetXaxis()->SetTimeDisplay(1);
  h->GetXaxis()->SetTimeFormat("%y/%m/%d/%H:%M");
  gStyle->SetTimeOffset(sdate.Convert());
  cout << sdate.GetDate() " " << sdate.GetTime() << endl;
  TCanvas *c = new TCanvas("c", "", 50, 50, 800, 300);
  h->Draw();
  c->Update();
}